Post on 09-Jun-2019
ULTRASOUND OF THYROID NODULES Jennifer A. Sipos, MD
Evaluation and Analysis of Thyroid Nodules
Jennifer A. Sipos, MDAssociate Professor
Division of EndocrinologyThe Ohio State University
Thyroid Ultrasound
1. Diagnostic use compared to physical examination
2. US predictors of malignancy3. US as a guide for what to FNA
Palpation is NOT sensitive or specific for detection of thyroid nodules
16% of patients with a palpable abnormality on PE will have no nodules on US
15% of patients will have another nodule on US that was not palpable on PE
Brander, J Clin Ultrasound 1992; Marqusee, Ann Intern Med 2000; Tan, Arch Intern Med 1995
How good are we at finding nodules?Ultrasound vs. Palpation
Brander 1992 J Clin Ultrasound 20: 37-42
# N
odul
es fo
und
by U
S
94%
50%
Nodule size by US
Palpable Thyroid Nodules
Nonpalpable Thyroid Nodules
Not all that is palpable is a nodule…..
Thyroid sonography should be performed in all patients with known or suspected thyroid nodules.Strong recommendation, high-quality evidence
Thyroid Nodule Management Guidelines
US evaluation is recommended for patients who are at risk for thyroid malignancy, have palpable thyroid nodules or goiter, or neck lymphadenopathy suggestive of a malignant lesion. Gharib et al 2016 Endo Practice 22: 622
Haugen et al 2016 Thyroid 26: 1-133
US Prediction of Thyroid CancerEchogenicity
• Normal thyroid is homogeneously hyperechoic compared to the strap muscles
• Normal thyroid is of similar echogenicity to the submandibular gland
• Nodule echogenicity is defined relative to the normal thyroid (?Hashi’s background)– Isoechoic– Hyperechoic– Hypoechoic Sensitivity 81%, Specificity 53%– marked hypoechogenicity, defined as relative to
strap muscles1
1Kim et al, AJR 2002
Normal Thyroid Echogenicity
Submandibular Gland
Sagittal View, Thyroid
Echogenicity
Hyperechoic
Isoechoic
Hypoechoic
Anechoic
Markedly Hypoechoic
Hypoechoic nodule
Markedly hypoechoic nodule1
[sensitivity 27%, specificity 94%]
Isoechoic nodule
1Kim et al, AJR 2002
Iso- or Hyperechoic nodules
Follicular carcinoma
If uniformly solid or associated with an irregular halo concerning for a neoplasm often a follicular or Hurthle cell adenoma or carcinoma
Hyperplastic nodule
If associated with minute cystic spaces hyperplastic
Slide courtesy of: S. Mandel
Hyperechoic area in thyroiditis
• Hyperechoic masses are usually benign (Hurthle cell aggregates)
• “white knight”
Takashima S et al, Radiology 1992;185:125-130; Bonavita AJR 2009; 193:207-13
Posterior Acoustic Enhancement
Posterior Acoustic Enhancement = Cystic
Absence of posterior acoustic enhancement = solid
Posterior acoustic enhancement in a solid nodule
Cystic change
• 30-50% of nodules have cystic change
• Simple cysts=rare <2%
Cystic change• 360 thyroid cancers at
Mayo Clinic:Solid: 78%<50% cystic: 19%>50% cystic: 3% and another
suspicious sonographic feature present1
Cystic papillary cancer1Henrichsen et al, RSNA 2005
Comet tail reverberation artifact
microcalcifications
Spongiform nodules
CalcificationsMicrocalcifications
(psammomatous) in papillarythyroid cancer
Coarse calcifications infollicular thyroid cancer
Microcalcifications
• multiple bright (< 1 mm) echoes without shadowing usually in a HYPOechoic nodule
• pitfall: colloid with reverberation artifact (“comet tail”) in a hyperplastic nodule
Microcalcifications Comet-tail artifact
Punctate Calcifications
Comet-tail artifact
Coarse calcifications
• Larger than 1mm—look for posterior signal dropout• Coarse calcifications common in lymphocytic thyroiditis
secondary to dystrophic calcifications • Present in parenchyma WITHOUT associated nodule• Concerning for malignancy if mixed with
microcalcifications or present in a SOLID nodule
Other calcifications
Signal drop-out
Eggshell
Eggshell calcificationsComplete, regular or “eggshell”
Interrupted
Papillary cancer
Follicular cancerUsually benign
NOT microcalcifications!!!
Small hyperechoic linear streaks just posterior to small cystic area posterior acoustic enhancement!
Association of Calcifications with Malignancy c/w with Absence of
Calcifications
• Micro calcifications- 3x risk• Central coarse calcifications - 2x risk• Peripheral/eggshell calcifications- 2x risk
Frates MC et al, J Clin Endo Metab 2006; 91:3411-3417
US Prediction of Thyroid CancerMargins
• Well-defined and regular• Infiltrative, spiculated, microlobulated1
– Sensitivity 55%, Specificity 79%– some malignant nodules have a predominately regular
border but are irregular in only small portion requiring high-resolution technique
• Irregular is NOT the same as INFILTRATIVE
1Kim et al, AJR 2002
Infiltrative Borders
Blurred margins
US Prediction of Thyroid CancerHalo
• Hypoechoic or sonolucent rim surrounding the nodule (thought to represent the compressed perinodular vessels)– present – absent-suggestive of an infiltrative malignancy
Sensitivity 66%, Specificity 43%• A thick, irregular halo is more suggestive of a
neoplasm (CAPSULE --follicular or Hurthle cell carcinoma or adenoma; encapsulated papillary cancer)1
1Cerbone et al, Hormone Res 1999
Thick, irregular haloThin halo
Thin halo is compressed blood vessels Follicular cancer
Halo
Absent Halo
US Prediction of Thyroid CancerTaller than wide
• Nodule is taller than wide on the transverse view
Kim AJR 2002; Cappelli Clin Endocrinol 2005; Moon Radiology 2008
Height greater than width
US Predictors of Malignancy for Thyroid Nodules
US feature Mean sensitivity(range)
Mean specificity(range)
Increased flow 77 (57-92) 79 (35-97)
Irregular borders 58 (48-78) 85 (74-95)
Taller than wide 58 (33-84) 81 (60-92)
Hypoechogenicity 53 (26-87) 73 (43-94)
Microcalcifications 42 (29-59) 91 (86-95)
*Review of 15 large studies
Sipos JA, Thyroid 2009;19:1363-1372
Haugen et al 2016 Thyroid 26: 1-133
Benign<1%
FNA not indicated
Simple Cysts
Haugen et al 2015 Thyroid
Spongiform
Partially cystic no suspicious features
Very low suspicion<3%
FNA ≥2cm
Haugen et al 2015 Thyroid
Low suspicion5-10%
FNA ≥ 1.5cm
Hyperechoic solid regular margin
Partially cystic with eccentric solid
Isoechoic solid regular margin
Haugen et al 2015 Thyroid
Sonographic featuresPapillary vs Follicular Thyroid Cancers
Jeh 2007 Korean J Radiol 8: 192-7
Per
cent
(%)
Sonographic featuresFVPTC vs Conventional PTC
Kim 2009 J Ultrasound Med 28: 1685-1692
Per
cent
(%)
Intermediate Suspicion10-20%FNA ≥1cm
Hypoechoic solid, regular margin
Haugen et al 2015 Thyroid
High Suspicion70-90%FNA ≥1cm
Solid hypoechoic nodule or a solid hypoechoic component in a partially cystic nodule with one or more features: irregular margins, microcalcifications, taller than wide shape, disrupted rim calcifications or ETE
Haugen et al 2015 Thyroid
Summary
• US of the neck for all patients suspected of having a thyroid nodule
• Individual sonographic features for characterization
• Pattern recognition for malignancy risk